The present invention relates to a copolymer in which certain fluorocarbons such as perfluoroacrylates and certain optionally substituted N-(oxymethyl)-acrylamide monomers, such as IBMA, are grafted onto a poly(oxyalkylene) compositions. The crosslinkable graft copolymer according to the present invention has a number of surprising properties including the fact that prior to crosslinking it is hydrophilic while subsequent to crosslinking, it becomes hydrophobic.
A variety of fluorocarbon surface treatments are recognized in the art. However, these fluorocarbon materials suffer from a number of drawbacks.
For example, the art employed these fluorocarbon materials in solvents such as chlorofluorocarbons (CFC) and/or a volatile organic compounds (VOC) which solvents are clearly not favored in view of those environmental problems associated with their use.
In addition, these fluorocarbon materials also suffer from inadequate wetting characteristics. In particular, these fluorocarbons are not free flowable upon removal of the solvent. Instead, they are a viscous, glassy solid at room temperature. Furthermore, they are still not considered flowable even upon exposure to moderate temperatures, i.e., 150.degree.-180 .degree. C.
The importance of this disadvantage can be found in the fact that due to their inadequate wetting characteristics, the uniformity of their treatment is erratic, i.e., the active solids do not form a uniform coating or treatment onto the substrate to which they are applied.
These fluorocarbon materials currently employed in the art are typically mixed with resins such as polyurethane which act as an adhesive for bonding the fluorocarbons to the fiber. However, due to the surface energy associated with these traditional fluorocarbons, one still does not obtain adequate "wetting" on the fiber surface.
The grafting of olefinic materials to organic compounds has also been recognized in the art.
For example, U.S. Pat. No. 3,418,354 to Wheeler relates a process for producing an olefin-poly(oxyalkylene) graft copolymer in which an olefin and a peroxide compound containing a peroxide group linked to a tertiary carbon atom are slowly and simultaneously added to a poly(oxyalkylene) compound.
This patent also discusses the ability to produce graft copolymers from certain fluoro-olefins. However, these fluoro-olefins are volatile materials and thus difficult to work with as illustrated by the use of high pressure vessels within the examples of this patent.
In addition, U.S. Pat. No. 4,463,035 to Green and U.S. Pat. No. 4,463,036 to Totten and Sabia, both relate to the production of graft copolymers where certain N-(oxymethyl)-acrylamide compounds, such as IBMA, are grafted onto a poly(oxyalkylene). In each patent, the graft polymers are employed as a finish for textile fibers.
However, the graft copolymers recognized within the art suffer from certain undesirable limitations. For example, the graft copolymers disclosed in the Green and Totten et al patents provide a hydrophilic surface treatment for fibers and textiles and thus, are not useful in a variety of environments.
Accordingly, the need still exists for an improved coating for use with fibrous materials.